Physical keyboards are the most ubiquitous input devices for users to enter data and commands into computers. Typing is a widely known and commonly practiced skill. When digital computing became a reality, physical keyboards having the standard typewriter key layout (commonly known as the “QWERTY” key layout) naturally became the standard input means for a user to enter data into a computer. By typing on a keyboard, a user can enter a large amount of textual data into the computer quickly.
Touch sensitive displays have also been used for a long time for computer user interface purposes, and are widely used on customer service devices, such as automatic teller machines, where user input options are often limited and simple and the speed of data entry is not a concern. An important advantage of a touch sensitive display device is that the same device serves as both an output device for presenting user-viewable images and an input device for entering user selections. User selectable options are typically presented as graphic features, such as user-selectable buttons or icons, on the touch sensitive screen, and the user selects an option by touching the graphic feature associated with that option. The location of the touch is detected by the device and used to determine which option has been selected.
As the computer technology advances and our dependence on computing devices for daily functions increases, the portability of computing devices becomes an increasingly important issue. For example, Personal Digital Assistance (PDA) devices have become very popular largely due to their portability. In order to be compact and portable, such devices typically do not have a physical keyboard. Instead, they use a touch sensitive screen for both input and output. Typically, a user enters textual data by pressing the keys of a miniature keyboard image displayed on the touch sensitive screen with a small stylus. The problem with such a miniature “virtual” keyboard is that it is very inconvenient to use, as the user has to “hunt and peck” the keys one by one with the stylus, making data entry a very slow and tedious process.
The trend to make computing devices portable and versatile is evidenced by the recent development of a new generation of smart display devices that run the Windows CE operating system of the Microsoft Corporation. One of such new display devices is a tablet-like detachable monitor for a personal computer (PC). The monitor has a touch sensitive screen and, once detached from the computer, communicates wirelessly with the computer to work as a portable monitor. Using this portable touch-sensitive display device, a user can move around the office or house while using the computer to respond to e-mail messages, edit documents, browsing the World Wide Web, etc., without having to be tied to the location of the computer. Since portability is one of its main features, this portable monitor device does not require a physical keyboard and uses its touch screen for user input when it is detached from the computer.
One of the technical challenges in developing the portable monitor device is how to improve the user input functions to enable a user to easily and conveniently enter textual data into the computer. In contrast to PDAs that have limited processing power and serve limited functions, the portable monitor device is wirelessly connected to the computer, and the user is likely to use the device for extensive editing and composing operations in the same way the user would when sitting in front the computer. The conventional “virtual keyboards” found on PDAs or the like are not satisfactory for input purposes because they do not feel or look like a regular physical keyboard and are not operated like a physical keyboard. What is needed is a virtual keyboard that can be used by a user like a regular physical keyboard to enter textual data conveniently and quickly. In other words, what is needed is a virtual keyboard that a user can use for “ten-finger” touch-typing as if it were a regular keyboard. It will be appreciated that a touch-typable virtual keyboard is not only useful for the aforementioned portable monitor device but can be advantageously used on many different touch-screen applications.